It is commonly known that micro-organisms can cause fouling and/or deterioration in construction, such as in buildings and in infrastructural constructions. An example of microbial fouling is fouling due to algae. Such fouling mostly leads to an undesirable staining of the construction. Another frequently observed form of fouling is fouling due to fungi. Especially in moist or damp environments, for example in a bathroom or shower, this often leads to undesirable staining. The removal of microbial fouling is often not easy and frequently requires chemicals that are environmentally harmful. Moreover, once the microbial fouling has been chemically removed, the fouling may return in time.
Making construction material resistant to microbial fouling, such as algae fouling and fungi fouling, is difficult because the construction materials, such as cement and plaster, typically have high pH values (often pH 10 or more). Inclusion of a biocide, such as a fungicide, into the construction materials in order to render them more resistant to microbial fouling normally leads to inactivation or even to degradation of the biocide due to the high pH levels. Due to the short leaching time of the biocides in the construction material the biocide has a reduced life span. As a consequence, in order to retain the resistance to microbial fouling over an extended period of time a high concentration of biocides in the construction materials is required. Such high concentrations of biocide have the disadvantage of inducing health problems and are therefore undesirable.